Design and Simulation of the Recirculating Crossed-Field Planar Amplifier

The Recirculating Planar Crossed-Field Amplifier (RPCFA) is a high power microwave device adapted from the Recirculating Planar Magnetron$^{\mathrm{1}}$, developed at the University of Michigan. A travelling-wave, rectangular, meander-line design has been developed in simulation that amplifies a 1.3 MW signal at 3 GHz to approximately 29 MW (13.5 dB) with nearly 53{\%} electronic efficiency. Simulation also shows that the RPCFA is zero-drive stable, e.g., output of any appreciable power is dependent on the presence of an input RF signal. The amplifier was designed to be driven by the Michigan Electron Long Beam Accelerator (MELBA), which is currently configured to deliver a -300 kV, 1-10 kA, 0.3-1.0 \textmu s pulse. Taking these parameters into consideration, a slow wave structure, cathode, and housing were designed using the finite element frequency domain code Ansys HFSS. The cold tube characteristics and RF field structures were then verified using the particle in cell code, MAGIC. Hot tube simulations on MAGIC were also run to calculate the RPCFA's performance, including gain and efficiency. Future work will include building a prototype RPCFA, cold testing, and performing experiments to verify the hot tube simulations. [1] R.M. Gilgenbach, Y.Y. Lau, D.M. French, B.W. Hoff, J. Luginsland, and M. Franzi, ``Crossed field device,'' U.S. Patent US 8 841 867B2, Sep. 23, 2014. [2] Developed by Alliant Techsystems